Child sexual abuse (CSA) is a terrible type of maltreatment that can have serious physical and psychological consequences for victims. These consequences include shame and are often taboo in conversation, which makes CSA very difficult to see. Therefore, multiple myths exist about CSA that can lead to misperceptions regarding issues such as its context, prevalence, and consequences. What is unknown cannot be addressed; therefore, the aim of this work was to investigate Spanish participants’ knowledge about CSA as well as examine gender and educational level differences. A 10-item questionnaire comprising myths and truths about CSA was developed, taking into account existing literature. Participants (N = 1,540) had to rate their level of agreement with the statements. Some important aspects of CSA remain unclear, particularly in terms of the background of the victims (e.g., gender, educational level, CSA prevalence). Significant differences in the perception of CSA between men and women and among those with various educational levels were found: Men and people with lower levels of education held more myths about CSA. In conclusion, better knowledge about CSA is needed to get people involved in its prevention. We must consider the myths and truths about CSA when designing prevention programs and tailor educational programs to the target population.